package com.wang.springframework.beans.factory.xml;

import cn.hutool.core.util.StrUtil;
import cn.hutool.core.util.XmlUtil;
import com.wang.springframework.beans.BeansException;
import com.wang.springframework.beans.PropertyValue;
import com.wang.springframework.beans.factory.config.BeanDefinition;
import com.wang.springframework.beans.factory.config.BeanReference;
import com.wang.springframework.beans.factory.support.AbstractBeanDefinitionReader;
import com.wang.springframework.beans.factory.support.BeanDefinitionRegistry;
import com.wang.springframework.core.io.Resource;
import com.wang.springframework.core.io.ResourceLoader;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;

import java.io.InputStream;

/**
 * @author wangjianhua
 * @Description xml读取bean
 * @date 2021/8/25/025 15:09
 **/
public class XmlBeanDefinitionReader extends AbstractBeanDefinitionReader {

    public XmlBeanDefinitionReader(BeanDefinitionRegistry registry) {
        super(registry);
    }

    public XmlBeanDefinitionReader(BeanDefinitionRegistry registry, ResourceLoader resourceLoader) {
        super(registry, resourceLoader);
    }

    @Override
    public void loadBeanDefinitions(Resource resource) throws BeansException {
        try {
            try (InputStream inputStream = resource.getInputStream()){
                doLoadBeanDefinitions(inputStream);
            }
        }
        catch (Exception e)
        {
            throw new BeansException("IOException parsing XML document from"+resource,e);
        }

    }

    @Override
    public void loadBeanDefinitions(Resource... resources) throws BeansException {
        for (Resource resource : resources) {
            loadBeanDefinitions(resource);
        }
    }

    @Override
    public void loadBeanDefinitions(String location) throws BeansException {
        ResourceLoader resourceLoader = getResourceLoader();
        Resource resource = resourceLoader.getResource(location);
        loadBeanDefinitions(resource);
    }

    @Override
    public void loadBeanDefinitions(String... locations) throws BeansException {
        for (String location : locations) {
           loadBeanDefinitions(location);
        }
    }

    protected void doLoadBeanDefinitions(InputStream inputStream) throws ClassNotFoundException{
        Document doc = XmlUtil.readXML(inputStream);
        Element root = doc.getDocumentElement();
        NodeList childNodes = root.getChildNodes();

        for (int i = 0; i < childNodes.getLength(); i++) {
            //判断元素
            if(!(childNodes.item(i) instanceof Element)){
                continue;
            }
            //判断对象
            if(!"bean".equals(childNodes.item(i).getNodeName())){
                continue;
            }

            //解析标签
            Element bean = (Element) childNodes.item(i);
            String id = bean.getAttribute("id");
            String name = bean.getAttribute("name");
            String className = bean.getAttribute("class");
            //获取class 方便获取类中的名称
            Class<?> clazz = Class.forName(className);

            //优先级 id>name
            String beanName = StrUtil.isNotEmpty(id)?id:name;
            if(StrUtil.isEmpty(beanName)){
                beanName = StrUtil.lowerFirst(clazz.getSimpleName());
            }

            //定义Bean
            BeanDefinition beanDefinition = new BeanDefinition(clazz);
            //读取属性并填充
            for (int j = 0; j < bean.getChildNodes().getLength(); j++) {
                if(!(bean.getChildNodes().item(j) instanceof Element)){
                    continue;
                }
                if(!"property".equals(bean.getChildNodes().item(j).getNodeName())){
                    continue;
                }

                //解析标签 property
                Element property = (Element)bean.getChildNodes().item(j);
                String attrName = property.getAttribute("name");
                String attrValue = property.getAttribute("value");
                String attrRef = property.getAttribute("ref");
                //获取属性值 引入对象、值对象
                Object value = StrUtil.isNotEmpty(attrRef)? new BeanReference(attrRef) : attrValue;
                //创建属性信息
                PropertyValue propertyValue = new PropertyValue(attrName,value);
                beanDefinition.getPropertyValues().addPropertyValue(propertyValue);
            }
            if(getRegistry().containsBeanDefinition(beanName)){
                throw new BeansException("Duplicate beanName["+beanName+"] is not allowed");
            }
            //注册beanDefinition
            getRegistry().registryBeanDefinition(beanName,beanDefinition);
        }
    }
}
